Electrically operated dipper trip



June 27, 1939. w, w, STEVENS 2,164,126

ELECTRICALLY OPERATED DIPPER TRIP Filed Nov. 10, 1938 Patented June 27, 1939 ELECTRICALLY OPERATED DIPPER TRIP Woodrow Wilson Stevens, Paducah', Ky., assignor of one-half to William B. Stone, Paducah, Ky.

Application November 10, 1938, Serial No. 239,871

4 Claims.

This invention relates to an electrically operated dipper trip and comprises a mechanism or an attachment for use with excavating machinery and particularly with excavating machinery known as power shovels.

The present improved dipper trip is so constructed as to be readily attachable to power shovels now in use and this is the case irrespective of whether said shovels are steam operated, electrically operated, operated by a combustion motor, or operated by some other Well known suitable power means.

The primary object of the invention is the provision of a dipper trip which is positive in action and is extremely simple of operation whereby the excavating capacity of the particular shovel to which it is attached is materially increased by reason of increased rapidity of dumping the load from the dipper or digger buckets.

Another and further object of the invention is the provision of a dipper trip which is so mounted and constructedas to be less likely to be injured or put out ofoperation by reason of falling rocks and crumbling banks which are a common occurrence in connection with the normal operation of an excavating machine of the type to which thepresent invention is applied.

Another and still further object of the invention is the provision of a dipper .trip which is extremely simple and cheap of manufacture and extremely simple and cheap of application] either to. new shovels or to shovels already in use and a trip which is positive in action and under the instant control of the shovel operator.

Other furtherand additional objects, novel features of construction and. improved results of the invention will appear in more detail from the following description when read in the light of the accompanying drawing.

In the drawing:

Fig. 1 is a side view of that part or portions of the excavating machine or shovel with whichthe present invention is associated and illustrates the application of a preferred embodiment of the present invention thereto.

Fig. 2 is a combined top plan and diagrammatic view of the invention.

Having reference now to the drawing in which like parts are designated by similar reference characters throughout the description and describing the invention in detail, A designates the usual and conventional shovel or excavator boom while B and C designate the usual and conventional dipper stick and dipper bucket respectively of the shovel.

with a conventional door or bottom D which is pivotally mounted as at l to permit it to swing to an open position to dump its load.

To those skilled in this art it is not necessary to describe the operation and construction of the 5 excavator or shovel itself but it is suflicient to say that there is the usual cab (not shown) in which are disposed the controls through which the operator manipulates the boom and dipper stick and that the dipper or bucket itself is movable in respect to the dipper stick by being pivotally mounted thereon as at 2. The movement of the dipper itself is obtained through suitable cables or linkage 3 which has driving connection with whatever power means is used, which power means is mounted within the excavator cab.

It will also be well understood that it is conventional in practice to provide a latch for holding the dipper door D in a closed position and that once the dipper latch is released and the door opened the door is caused to assume a closed position and again become latched by manipulation of the dipper boom B and the dipper C by the operator of the excavator through proper control of the control elements within the excavator cab.

Having particular reference now to the mechanism and apparatus constituting the present invention it will be seen that I have provided a metallic plate E which is of an L-shape in cross section and have attached this to the dipper stick B adjacent the upper or outer end thereof in a manner whereby the horizontal leg 4 of the plate rests upon the top of the leg 5 of the dipper stick and as suitably secured thereto by a series of bolts, rivets or the like 6. Attachment of the plate in this manner permits the vertical leg 1 of the plate to extend downwardly in parallelism to the outer side 8 of the dipper stick leg 5.

At or adjacent its inner end the horizontal leg 4 of the plate is provided with an outwardly extending and horizontally disposed and substantially rectangular bracket plate 9 to the under side of which is suitably secured an electric motor H] by bolts II or the like. The disposition of the motor is such that its shaft l2 extends outwardly at right angles to the vertical leg I of the plate E.

A stub shaft I3 arranged in spaced relationship to the motor and extending outwardly from the vertical leg! of the plate E carries a pulley I4 which has driving connection with the electric motor I0 through a suitable belt I5. I have found from actual practice that a V type belt is preferable for use in the present combination.

The pulley is provided with an eccentrically disposed outwardly extending stub shaft or pin Hi to which is rotatably secured one end of a connecting rod I! the other end of which is rotatably secured to a pin I8 carried by the upper end of a lever I9 the lower end of which is pivotally mounted as at 20 on a bracket 2| which is suitably secured to or could be formed as a part of the leg of the dipper stick.

The lever intermediate its length is notched out as at 22 to engage an outwardly extending pin 23 carried by the dipper stick and a coil spring 24 tends normally to hold the lever in engagement with this pin or stop.

Connection between the latch of the door D of the dipper and the lever I9 is had through a chain 25 although it is to be understood that a cable or other suitable connecting means could be substituted. In the past it has been conventional practice to utilize a chain connection to the dipper latch and such mechanism as has been utilized for operating the latch.

Power for the electric motor I!) is obtained through an electric battery F. I have found a 12 volt battery to be sufficiently powerful to serve the purposes of the present invention. The battery would preferably be located in the cab of the excavating machine and has been found to be a desirable manner of providing current for the excavator in that excavators are moved from one job to another and it is preferable to provide the source of energy for the electric motor in a form to travel with the excavating machine.

The electric wires interconnecting the battery and the motor are designated as 26 and 2'! respectively and include a relay switch 28. For the purpose of clearly illustrating the electrical layout utilized each conductor 26 and 2'! is illustrated separately but it will be understood that these conductors will be contained within a flexible conduit such as is illustrated at 29 in Fig. 1 of the drawing and that sufficient slack will be provided so as to accommodate or permit the customary movement of the excavator boom and dipper stick incident to the normal usage of the shovel.

To provide for instant operation of the mechanism to trip the latch of the dipper door a push button 30 is provided in the handle 3| of any one of the several conventional operating levers positioned in the cab of the machine and utilized by the operator when the excavator is performing its normal operations. This push button 30 is electrically connected through suitable conductors 32 and 33 to the relay switch 28.

From the foregoing description it will be seen that I have provided an extremely cheap and simple mechanism for operating the door latch of the dipper of an excavatingmachine andits operation is sufficiently obvious as not to necessitate a description thereof. To those skilled in the art it will be apparent and well known that in all excavating machines the doors D will close themselves by the proper manipulation of the control elements of the machine and it will be further apparent that the weight of the door, after current delivery to the motor has been. broken, will always cause the motor to stop in the proper position to permit the door to be closed and latched.

From actual practice I have found that with the use of the present improved trip the output of the excavating machine has been increased ten percent and I have further found that when the machine is digging in a bank which crumbles off, as happens many times in the course of a days work, dirt and rock which fall will not foul the motor or the other working parts of the apparatus and that should a rock strike the drive belt IE or become wedged between the belt and the dipper stick the belt provides sufficient resiliency or give as to prevent injury to the parts. I have found this to be of great importance and consitutes a decided advantage over such dipper trip mechanisms and apparatus which are now in use and with which I am familiar.

I claim:

1. In an excavator, the combination of a dipper stick carrying a dipper bucket provided with a dump door, a latch for said door, a plate extending outwardly at right angles from said stick, an electric motor mounted on the under side of said plate and protected thereby from falling rock and dirt during the digging operation of said dipper bucket, a pulley rotatably mounted on the side of said dipper stick, a drive belt interconnecting said motor and said pulley, a bracket extending downwardly from said dipper stick, a lever pivotally mounted on said bracket, a connecting rod eccentrically connected to said pulley and connected to said lever to oscillate the same when said pulley is rotated, a stop pin, resilient means normally holding said lever against said stop pin, a chain interconnecting said lever and said latch, a source of electric current having connection with said motor through a relay switch, and a second switch positioned convenient to the operator of said excavator and in the circuit to said motor for causing the operation of said relay switch to control the delivery of current to said motor.

2. In an excavator, the combination of a dipper stick carrying a dipper having a dump door provided with a latch, an elongated plate of an L- shape in cross section having one leg secured to the upper face of the dipper stick and its other leg extending downwardly and paralleling the side wall of said stick, a second plate extending outwardly from said first named plate and outwardly at right angles from said stick, an electric motor mounted on the under side of said second plate and protected thereby from falling rock and dirt during the digging operation of said dipper bucket, a stub shaft extending outwardly from that leg of the first plate paralleling the side of the dipper stick, a pulley rotatably mounted on said stub shaft, a drive belt interconnecting said motor and said pulley, a bracket extending downwardly from said dipper stick, a lever pivotally mounted on said bracket, a connecting rod eccentrically connected to said pulley and connected to said lever to oscillate the same when said pulley is rotated, a stop pin between said lever and said dipper bucket, resilient means normally holding said lever against said stop pin and towards said dipper bucket, a chain interconnecting said lever and said latch, a source of electric current having connection with said motor through a relay switch, a second switch positioned convenient to the operator of said excavator and electrically connected to said relay switch for causing said relay switch to be opened and closed upon operation of said second switch.

3. In an excavator, the combination of a dipper stick carrying a dipper having a dump door provided with a latch, a plate extending outwardly from said stick, an electric motor carried by the under side of said plate and protected thereby from falling rock and dirt, a pulley on said stick, a flexible drive element interconnecting said motor and said pulley, a lever pivotally mounted on said stick and having operative connection with the latch of said dump door, a rod eccentrically connected to said pulley and connected to said lever for rocking said lever on its pivotal support, a source of electric energy for said motor, and switch means conveniently located to the operator of said excavator for turning on and off the delivery of current to said motor.

4. In an excavator, the combination of a dipper stick carrying a dipper having a dump door provided with a latch, a plate carried by said dipper stick and arranged in separated parallel relationship to the outer side Wall of said stick, a second plate extending outwardly from said stick, an electric motor mounted on the under side of said second plate and protected thereby from falling rock and dirt during digging operations of said dipper bucket, a stub shaft extending outwardly from said first named plate, a pulley rotatably mounted on said stub shaft, a flexible drive element interconnecting said motor and said pulley, a lever pivotally mounted on said stick, a connecting rod eccentrically connected to said pulley and connected to said lever to oscillate the same when said pulley is rotated, a stop pin between said lever and said dipper bucket, resilient means tending normally to hold said lever against said pin, means operatively interconnecting said lever and said latch, a source of electric current having connection with said motor, and a switch positioned convenient to the operator of said excavator for controlling the delivery of current to said motor.

WOODROW WILSON STEVENS. 

